The prospect of precision therapy for renal cell carcinoma

Unfolding the mysteries of heterogeneity from a high-resolution perspective: integration analysis of single-cell multi-omics and spatial omics revealed functionally heterogeneous cancer cells in ccRCC

The genomic landscape of clear cell renal cell carcinoma (ccRCC) has a considerable intra-tumor heterogeneity, which is a significant obstacle in the field of precision oncology and plays a pivotal role in metastasis, recurrence, and therapeutic resistance of cancer. The mechanisms of intra-tumor heterogeneity in ccRCC have yet to be fully established. We integrated single-cell RNA sequencing (scRNA-seq) and transposase-accessible chromatin sequencing (scATAC-seq) data from a single-cell multi-omics perspective. Based on consensus non-negative matrix factorization (cNMF) algorithm, functionally heterogeneous cancer cells were classified into metabolism, inflammatory, and EMT meta programs, with spatial transcriptomics sequencing (stRNA-seq) providing spatial information of such disparate meta programs of cancer cells. The bulk RNA sequencing (RNA-seq) data revealed high clinical prognostic values of functionally heterogeneous cancer cells of three meta programs, with transcription factor regulatory network and motif activities revealing the key transcription factors that regulate functionally heterogeneous ccRCC cells. The interactions between varying meta programs and other cell subpopulations in the microenvironment were investigated. Finally, we assessed the sensitivity of cancer cells of disparate meta programs to different anti-cancer agents. Our findings inform on the intra-tumor heterogeneity of ccRCC and its regulatory networks and offers new perspectives to facilitate the designs of rational therapeutic strategies.

c-MET pathway in human malignancies and its targeting by natural compounds for cancer therapy

BACKGROUND

c-MET is a receptor tyrosine kinase which is classically activated by HGF to activate its downstream signaling cascades such as MAPK, PI3K/Akt/mTOR, and STAT3. The c-MET modulates cell proliferation, epithelial-mesenchymal transition (EMT), immune response, morphogenesis, apoptosis, and angiogenesis. The c-MET has been shown to serve a prominent role in embryogenesis and early development. The c-MET pathway is deregulated in a broad range of malignancies, due to overexpression of ligands or receptors, genomic amplification, and MET mutations. The link between the deregulation of c-MET signaling and tumor progression has been well-documented. Overexpression or overactivation of c-MET is associated with dismal clinical outcomes and acquired resistance to targeted therapies. Since c-MET activation results in the triggering of oncogenic pathways, abrogating the c-MET pathway is considered to be a pivotal strategy in cancer therapeutics. Herein, an analysis of role of the c-MET pathway in human cancers and its relevance in bone metastasis and therapeutic resistance has been undertaken. Also, an attempt has been made to summarize the inhibitory activity of selected natural compounds towards c-MET signaling in cancers.

METHODS

The publications related to c-MET pathway in malignancies and its natural compound modulators were obtained from databases such as PubMed, Scopus, and Google Scholar and summarized based on PRISMA guidelines. Some of the keywords used for extracting relevant literature are c-MET, natural compound inhibitors of c-MET, c-MET in liver cancer, c-MET in breast cancer, c-MET in lung cancer, c-MET in pancreatic cancer, c-MET in head and neck cancer, c-MET in bone metastasis, c-MET in therapeutic resistance, and combination of c-MET inhibitors and chemotherapeutic agents. The chemical structure of natural compounds was verified in PubChem database.

RESULTS

The search yielded 3935 publications, of which 195 reference publications were used for our analysis. Clinical trials were referenced using ClinicalTrials.gov identifier. The c-MET pathway has been recognized as a prominent target to combat the growth, metastasis, and chemotherapeutic resistance in cancers. The key role of the c-MET in bone metastasis as well as therapeutic resistance has been elaborated. Also, suppressive effect of selected natural compounds on the c-MET pathway in clinical/preclinical studies has been discussed.

Identification of Immune-Related Seven-Long Non-Coding RNA Signature for Overall Survival and Validation of the Effect of LINC01270 in Malignant Phenotypes of Clear Cell Renal Carcinoma

Introduction

The overall survival of patients with high-stage clear cell renal carcinoma (ccRCC) is poor. However, promising molecular-level prognostic marker is still lacking to date.

Methods

We systematically evaluated the prognostic potential of immune-related long non-coding RNAs (lncRNAs) in ccRCC. The expressions of lncRNAs were validated in clinical tissues of ccRCC. Functional experiments were performed to investigate the role of lncRNAs in ccRCC.

Results

Eight hundred and ninety-three lncRNAs were differentially expressed in ccRCC and compared with normal controls and were screened out using three independent cohorts. Among them, 290 immune-related lncRNAs were identified. We identified a seven-lncRNA signature (LINC01270, FIRRE, RP11-37B2.1, RP11-253I19.3, RP11-438L19.1, RP11-504P24.9, and CTB-41I6.1) associated with the overall survival of late-stage ccRCC patients. Further multivariate Cox analysis using clinical factors as covariates showed that our lncRNA signature was an independent biomarker in training (P < 0.001, Log rank test) and validation cohorts (P = 0.003). The seven lncRNAs were closely related to the major targets (PD-1, PD-L1, and CTLA4) of immune checkpoint blockade drugs, implying that they may have potential value in predicting immunotherapy response. The seven lncRNAs may play an important role in tumor-infiltrating immune cells (eg, T/B cells) and tumor progression through regulating the binding of protein receptors/complexes, as revealed by functional analysis. qRT-PCR showed that LINC01270 was upregulated in ccRCC tissues (n=20) compared with paired normal samples. Functional experiments showed that LINC01270 silencing inhibited the proliferation, invasion, and migration of ccRCC cells.

Discussion

In summary, the seven-lncRNA signature has great potential in prognosis for patients with late-stage ccRCC, which could be a novel clinical biomarker. LINC01270 could be a novel therapeutic target of ccRCC.

Hybrid Metabolic Activity-Related Prognostic Model and Its Effect on Tumor in Renal Cell Carcinoma

Background

Tumor cells with a hybrid metabolic state, in which glycolysis and oxidative phosphorylation (OXPHOS) can be used, usually have a strong ability to adapt to different stress environments due to their metabolic plasticity. However, few studies on tumor cells with this phenotype have been conducted in the field of renal cell carcinoma (RCC).

Methods

The metabolic pathway (glycolysis, OXPHOS) related gene sets were obtained from the Molecular Signatures Database (V7.5.1). The gene expression matrix, clinical information, and mutation data were obtained by Perl programming language (5.32.0) mining, the Cancer Genome Atlas and International Cancer Genome Consortium database. Gene Set Enrichment Analysis (GSEA) software (4.0.3) was utilised to analyse glycolysis-related gene sets. Analysis of survival, immune infiltration, mutation, etc. was performed using the R programming language (4.1.0).

Results

Eight genes that are highly associated with glycolysis and OXHPOS were used to construct the cox proportional hazards model, and risk scores were calculated based on this to predict the prognosis of clear cell RCC patients and to classify patients into risk groups. Gene Ontology, the Kyoto Encyclopaedia of Genes and Genomes, and GSEA were analysed according to the differential genes to investigate the signal pathways related to the hybrid metabolic state. Immunoinfiltration analysis revealed that CD8+T cells, M2 macrophages, etc., had significant differences in infiltration. In addition, the analysis of mutation data showed significant differences in the number of mutations of PBRM1, SETD2, and BAP1 between groups. Cell experiments demonstrated that the DLD gene expression was abnormally high in various tumor cells and is associated with the strong migration ability of RCC.

Conclusions

We successfully constructed a risk score system based on glycolysis and OXPHOS-related genes to predict the prognosis of RCC patients. Bioinformatics analysis and cell experiments also revealed the effect of the hybrid metabolic activity on the migration ability and immune activity of RCC and the possible therapeutic targets for patients.

Precision Medicine: An Optimal Approach to Patient Care in Renal Cell Carcinoma

Renal cell cancer (RCC) is a heterogeneous tumor that shows both intra- and inter-heterogeneity. Heterogeneity is displayed not only in different patients but also among RCC cells in the same tumor, which makes treatment difficult because of varying degrees of responses generated in RCC heterogeneous tumor cells even with targeted treatment. In that context, precision medicine (PM), in terms of individualized treatment catered for a specific patient or groups of patients, can shift the paradigm of treatment in the clinical management of RCC. Recent progress in the biochemical, molecular, and histological characteristics of RCC has thrown light on many deregulated pathways involved in the pathogenesis of RCC. As PM-based therapies are rapidly evolving and few are already in current clinical practice in oncology, one can expect that PM will expand its way toward the robust treatment of patients with RCC. This article provides a comprehensive background on recent strategies and breakthroughs of PM in oncology and provides an overview of the potential applicability of PM in RCC. The article also highlights the drawbacks of PM and provides a holistic approach that goes beyond the involvement of clinicians and encompasses appropriate legislative and administrative care imparted by the healthcare system and insurance providers. It is anticipated that combined efforts from all sectors involved will make PM accessible to RCC and other patients with cancer, making a tremendous positive leap on individualized treatment strategies. This will subsequently enhance the quality of life of patients.

Bioinformatics Study Identified EGF as a Crucial Gene in Papillary Renal Cell Cancer

Background

Due to a lack of knowledge of the disease process, papillary renal cell carcinoma (PRCC) has a dismal outlook. This research was aimed at uncovering the possible biomarkers and the underlying principles in PRCC using a bioinformatics method.

Methods

We searched the Gene Expression Omnibus (GEO) datasets to obtain the GSE11151 and GSE15641 gene expression profiles of PRCC. We used the R package limma to identify the differentially expressed genes (DEGs). The online tool DAVID and ClusterProfiler package in R software were used to analyze Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway dominance, respectively. The STRING database was utilized to construct the PPI network of DEGs. Using the Cytoscape technology, a protein-protein interaction (PPI) network that associated with DEGs was created, and the hub genes were identified using the Cytoscape plug-in CytoHubba. The hub genes were subjected to a Kaplan-Meier analysis to identify their correlations with survival rates.

Results

From the selected datasets, a total of 240 common DEGs were identified in the PRCC, including 50 upregulated genes and 190 downregulated regulated genes. Renal growth, external exosome, binding of heparin, and metabolic processes were all substantially associated with DEGs. The CytoHubba plug-in-based analysis identified the 10 hub genes (ALB, KNG1, C3, CXCL12, EGF, TIMP1, VCAN, PLG, LAMC1, and CASR) from the original PPI network. The higher expression group of EGF was associated with poor outcome in patients with PRCC.

Conclusions

We revealed important genes and proposed biological pathways that may be implicated in the formation of PRCC. EGF might be a predictive biomarker for PRCC and therefore should be investigated as a novel treatment strategy.

Pharmacometabolomics Applied to Personalized Medicine in Urological Cancers

Prostate cancer (PCa), bladder cancer (BCa), and renal cell carcinoma (RCC) are the most common urological cancers, and their incidence has been rising over time. Surgery is the standard treatment for these cancers, but this procedure is only effective when the disease is localized. For metastatic disease, PCa is typically treated with androgen deprivation therapy, while BCa is treated with chemotherapy, and RCC is managed primarily with targeted therapies. However, response rates to these therapeutic options remain unsatisfactory due to the development of resistance and treatment-related toxicity. Thus, the discovery of biomarkers with prognostic and predictive value is needed to stratify patients into different risk groups, minimizing overtreatment and the risk of drug resistance development. Pharmacometabolomics, a branch of metabolomics, is an attractive tool to predict drug response in an individual based on its own metabolic signature, which can be collected before, during, and after drug exposure. Hence, this review focuses on the application of pharmacometabolomic approaches to identify the metabolic responses to hormone therapy, targeted therapy, immunotherapy, and chemotherapy for the most prevalent urological cancers.

Associations of Genetic Polymorphisms of mTOR rs2295080 T/G and rs1883965 G/A with Susceptibility of Urinary System Cancers

Background. Genetic polymorphisms in mammalian target of rapamycin (mTOR) signaling axis can influence the susceptibility of cancer. The relationship between mTOR gene variants rs2295080 T/G and rs1883965 G/A and the risk of cancer remains inconsistent. The present study is aimed at comprehensively investigating the association between mTOR polymorphisms and susceptibility to cancer. Methods. We conducted a comprehensive assessment using odds ratios (ORs), corresponding 95% confidence intervals (CIs), and in silico tools to evaluate the effect of mTOR variations. Immunohistochemical staining (IHS) and GSEA analysis were used to investigate the expression of mTOR in urinary system cancer. Results. The pooled analysis involved 22 case-control studies including 14,747 cancer patients and 16,399 controls. The rs2295080 T/G polymorphism was associated with the risk of cancer (G-allele versus T-allele, $\text{OR}=0.89$ , $95\%\text{CI}=0.80$ –0.98, $P=0.023$ ; GT versus TT, $\text{OR}=0.88$ , $95\%\text{CI}=0.81$ –0.96, $P=0.004$ ; GG+GT versus TT, $\text{OR}=0.87$ , $95\%\text{CI}=0.78$ –0.96, $P=0.008$ ), especially for cancers of the urinary system, breast, and blood. Variation rs1883965 G/A was associated with cancer susceptibility, especially for digestive cancer. IHS analysis showed that mTOR was upregulated in prostate and bladder cancer. GSEA revealed that the insulin signaling pathway, lysine degradation pathway, and mTOR signaling pathway were enriched in the high mTOR expression group. Conclusions. The mTOR rs2295080 T/G polymorphism may be associated with susceptibility of urinary cancer. The expression of mTOR is positively correlated with tumor malignancy in prostate cancer.

An up-to-date evaluation of cabozantinib for the treatment of renal cell carcinoma

Introduction: In the evolving treatment scenario of metastatic renal cell carcinoma, cabozantinib is gaining increasing attention, presenting as a cornerstone therapy, both as a monotherapy and in combination with immune-checkpoint inhibitors.Areas covered: In this review, the authors explore the role of cabozantinib in the treatment of metastatic clear cell and non-clear cell renal cell carcinoma, presenting data from the most recent clinical trials and investigating ongoing studies. They, furthermore, evaluate the pharmacokinetic, pharmacodynamic, and immunomodulatory effect of cabozantinib, as well as underlining the tolerability profile and patients' quality of life.Expert opinion: Cabozantinib's administration as a single agent is restricted to intermediate- and poor-risk patients (according to IMDC criteria). The further advent of anti-VEGF-receptor tyrosine kinase inhibitors combined with immune checkpoint inhibitor regimens (such as pembrolizumab + axitinib) has allowed to expand the use of cabozantinib, leading to its combination with nivolumab. In the next few years, more information is required to look for the application of cabozantinib-based combinations as a later-line approach in metastatic RCC patients, beside their use in the first-line setting.

MicroRNA-203 inhibits epithelial-mesenchymal transition, migration, and invasion of renal cell carcinoma cells via the inactivation of the PI3K/AKT signaling pathway by inhibiting CAV1

The present study aimed to evaluate the underlying mechanism of microRNA-203 (miR-203) in renal cell carcinoma (RCC) involving the PI3K/AKT signaling pathway. The results revealed downregulated miR-203 and upregulated CAV1 in RCC tissues. Upregulated miR-203 and downregulated CAV1 increased E-cadherin expression and cell apoptosis, decreased β-catenin and N-cadherin expression and cell proliferation, migration and invasion, and blocked cell cycle entry. CAV1, a target gene of miR-203, decreased by up-regulated miR-203, and silencing CAV1 led to the inactivation of PI3K/AKT signaling pathway. In conclusion, our findings suggested that miR-203-mediated direct suppression of CAV1 inhibits EMT of RCC cells via inactivation of the PI3K/AKT signaling pathway.

HGF/c-MET pathway in cancer: from molecular characterization to clinical evidence

This review provides a comprehensive landscape of HGF/c-MET (hepatocyte growth factor (HGF) /mesenchymal-epithelial transition factor (c-MET)) signaling pathway in cancers. First, we generalize the compelling influence of HGF/c-MET pathway on multiple cellular processes. Then, we present the genomic characterization of HGF/c-MET pathway in carcinogenesis. Furthermore, we extensively illustrate the malignant biological behaviors of HGF/c-MET pathway in cancers, in which hyperactive HGF/c-MET signaling is considered as a hallmark. In addition, we investigate the current clinical trials of HGF/c-MET-targeted therapy in cancers. We find that although HGF/c-MET-targeted therapy has led to breakthroughs in certain cancers, monotherapy of targeting HGF/c-MET has failed to demonstrate significant clinical efficacy in most cancers. With the advantage of the combinations of HGF/c-MET-targeted therapy, the exploration of more options of combinational targeted therapy in cancers may be the major challenge in the future.

Pembrolizumab for the treatment of renal cell carcinoma

INTRODUCTION

The acquisition of resistance to VEGF-inhibiting therapies has prompted research toward immunotherapy for the treatment of metastatic renal cell carcinoma (mRCC). Among several, checkpoint inhibitors including PD-1 and PD-L1 inhibitors are the most promising approach.

AREAS COVERED

This review addresses the clinical efficacy of the anti-PD-1 monoclonal antibody pembrolizumab in first- and second-line treatment for mRCC regarding the most recent and significant published and ongoing studies. Attention is also given to its pharmacological characteristics as well as adverse events and its impact on patients' quality of life.

EXPERT OPINION

Immunotherapy has become the backbone for the treatment of advanced RCC. With the approval of several therapeutic options, research needs now to focus on defining the appropriate therapy for each patient. Axitinib plus pembrolizumab belongs to the combinations of tyrosine kinase inhibitors (TKI) plus immune checkpoint inhibitors for the first-line treatment of metastatic RCC. New combinations of pembrolizumab plus TKI for the evaluation in first- and second-line treatment of mRCC available. However, studies directly comparing the various treatment regimens using predictive biomarkers and long-term endpoints, including treatment-free survival, are lacking.

MK-6482 as a potential treatment for von Hippel-Lindau disease-associated clear cell renal cell carcinoma

INTRODUCTION

Von Hippel-Lindau (VHL) disease is an inherited autosomal dominant syndrome caused by a germline mutation and/or deletion of the VHL gene. Inappropriate hypoxia-inducible factor (HIF)-mediated transcription of proangiogenic and metabolic genes leads to the development of tumors and cysts in multiple organs. Surgery is a standard treatment for localized tumors with a risk of metastasis or organ dysfunction. Repeated surgeries cause substantial morbidity and have a major impact on quality of life. There is an urgent need to develop effective and safe systemic treatments for VHL disease manifestations. The small-molecule HIF 2 alpha inhibitor MK-6482 (belzutifan) has demonstrated significant efficacy in VHL disease related renal cell carcinomas, hemangioblastomas, and pancreatic neuroendocrine tumors while demonstrating an acceptable safety profile.

AREAS COVERED

This paper reviews the development of the HIF-2 alpha inhibitor, MK-6482, and discusses preliminary results of ongoing phase I/II studies in renal cell carcinoma (RCC) and VHL disease. An examination of ongoing clinical development of MK-6482 and perspectives on potential future developments and challenges are offered.

EXPERT OPINION

Because of its favorable safety profile, its clear efficacy in VHL disease, promising findings in sporadic, advanced RCC, and convenient oral formulation, MK-6482 is expected to become a leading treatment for VHL disease. Among other currently available oral agents, we believe that MK-6482 will be a preferred treatment for VHL-associated RCC.

A narrative review of individualized treatments of genitourinary tumors: is the future brighter with molecular evaluations?

Few molecular prognostic and predictive biomarkers have been identified so far in genitourinary tumors. We started from a literature search to explore the status of the art of molecular pathology tests as diagnostic, prognostic, predictive biomarkers in genitourinary cancers. Next generation sequencing approaches now provide mind-changing information in the fields of kidney cancer diagnosis, predictive oncology of urothelial cancer, understanding the causes of testicular and penile cancer, and the comprehension of the drivers of prostate cancer progression beyond androgen regulation. The classification of kidney cancer will be based soon on molecular changes. The causes of non-HPV related penile cancer are largely unknown. The emerging high incidence of testicular cancer could be explained only on the basis of molecular changes. The response to novel therapeutic agents in prostatic and urothelial cancer will require thorough molecular tumor characterization. The hereditary risk of patients with early onset prostate cancer and their potential treatment with targeted therapy requires germline and somatic genetic assays. The implementation of effective biomarkers for the response to immune check-point inhibitors in genitourinary cancer is based on the assessment of inflammatory expression profiles and the tumor mutational burden. This review deals with the current tests and provides a tentative foresee of the future molecular biomarkers of genitourinary cancer.

The crosstalk between HIFs and mitochondrial dysfunctions in cancer development

Mitochondria are essential cellular organelles that are involved in regulating cellular energy, metabolism, survival, and proliferation. To some extent, cancer is a genetic and metabolic disease that is closely associated with mitochondrial dysfunction. Hypoxia-inducible factors (HIFs), which are major molecules that respond to hypoxia, play important roles in cancer development by participating in multiple processes, such as metabolism, proliferation, and angiogenesis. The Warburg phenomenon reflects a pseudo-hypoxic state that activates HIF-1α. In addition, a product of the Warburg effect, lactate, also induces HIF-1α. However, Warburg proposed that aerobic glycolysis occurs due to a defect in mitochondria. Moreover, both HIFs and mitochondrial dysfunction can lead to complex reprogramming of energy metabolism, including reduced mitochondrial oxidative metabolism, increased glucose uptake, and enhanced anaerobic glycolysis. Thus, there may be a connection between HIFs and mitochondrial dysfunction. In this review, we systematically discuss the crosstalk between HIFs and mitochondrial dysfunctions in cancer development. Above all, the stability and activity of HIFs are closely influenced by mitochondrial dysfunction related to tricarboxylic acid cycle, electron transport chain components, mitochondrial respiration, and mitochondrial-related proteins. Furthermore, activation of HIFs can lead to mitochondrial dysfunction by affecting multiple mitochondrial functions, including mitochondrial oxidative capacity, biogenesis, apoptosis, fission, and autophagy. In general, the regulation of tumorigenesis and development by HIFs and mitochondrial dysfunction are part of an extensive and cooperative network.

Prognostic value of infiltrating immune cells in clear cell renal cell carcinoma (ccRCC)

In this study, we attempted to evaluate the prognostic value of infiltrating immune/stromal cells in clear cell renal cell carcinoma (ccRCC), by using the immune scores and stromal scores based on the "Estimation of STromal and Immune cells in MAlignant Tumours using Expression data" algorithm to represent the levels of infiltrating immune cells and stromal cells. We found that the infiltrating immune cells were associated with poor prognosis of ccRCC. To assess the role of infiltrating immune cells in ccRCC cells, first, we performed differentially expressed genes analysis and functional analysis for validation. The results showed that the underlying mechanism by which infiltrating immune cells promoted cancer progression involved in regulating the nuclear division, angiogenesis, and immune response. Next, we investigated the relationship between infiltrating immune cells and mutations in ccRCC cells. We found that the infiltrating immune cells have certain effects on genetic mutations. In conclusion, infiltrating immune cells within the tumor microenvironment can be used to predict prognosis in ccRCC.

Multi-omics analysis reveals epithelial-mesenchymal transition-related gene FOXM1 as a novel prognostic biomarker in clear cell renal carcinoma

Identification of novel clinical biomarker in clear cell renal carcinoma (ccRCC) is warranted. Integrating transcriptome (n=1669), DNA methylation (n=577) and copy number data (n=832), we developed a method to identify driver biomarkers by analyzing the omics-level dynamics of Epithelial-Mesenchymal Transition (EMT)-related genes in ccRCC. We first identified 504 expression dynamic changed genes involved in ccRCC-associated key pathways such as EMT, cell cycle, EGFR and PI3K/AKT signaling. Further analysis identified 229 (90 gene promoters) aberrant expression quantitative trait methylation (eQTM) and 256 genes with expression quantitative trait copy number (eQTCN) alterations. Among them, FOXM1 was affected by both eQTM and eQTCN. FOXM1 copy number amplification (115/500, 23% of patients), occurred in an amplified peak in chromosome 12q13.3, was enriched in late-stage ccRCC samples and was associated with worse survival. FOXM1-overexpressed pT3 patients with distant metastasis showed ~25% shorter overall survival in both training (log-rank P=0.006) and validation (log-rank P=0.018) cohorts. The eQTM-gene hybrid signature (cg00044170 and FOXM1), superior to either gene expression or DNA methylation alone, showed great potential in diagnosing localized ccRCC in training (area under curve = 0.958) and validation datasets. FOXM1 could be a novel prognostic biomarker and shed light for early diagnosis at molecular level in ccRCC.

mTOR: Role in cancer, metastasis and drug resistance

Mammalian target of rapamycin (mTOR) is a serine/threonine kinase that gets inputs from the amino acids, nutrients, growth factor, and environmental cues to regulate varieties of fundamental cellular processes which include protein synthesis, growth, metabolism, aging, regeneration, autophagy, etc. The mTOR is frequently deregulated in human cancer and activating somatic mutations of mTOR were recently identified in several types of human cancer and hence mTOR is therapeutically targeted. mTOR inhibitors were commonly used as immunosuppressors and currently, it is approved for the treatment of human malignancies. This review briefly focuses on the structure and biological functions of mTOR. It extensively discusses the genetic deregulation of mTOR including amplifications and somatic mutations, mTOR-mediated cell growth promoting signaling, therapeutic targeting of mTOR and the mechanisms of resistance, the role of mTOR in precision medicine and other recent advances in further understanding the role of mTOR in cancer.

miR-22 Regulates Invasion, Gene Expression and Predicts Overall Survival in Patients with Clear Cell Renal Cell Carcinoma

Background:

Clear cell renal cell carcinoma (ccRCC) is molecularly diverse and distinct molecular subtypes show different clinical outcomes. MicroRNAs (miRNAs) are essential components of gene regulatory networks and play a crucial role in progression of many cancer types including ccRCC.

Objective:

Identify prognostic miRNAs and determine the role of miR-22 in ccRCC.

Methods:

Hierarchical clustering was done in R using gene expression profiles of over 450 ccRCC cases in The Cancer Genome Atlas (TCGA). Kaplan-Meier analysis was performed to identify prognostic miRNAs in the TCGA dataset. RNA-Seq was performed to identify miR-22 target genes in primary ccRCC cells and Matrigel invasion assay was performed to assess the effects of miR-22 overexpression on cell invasion.

Results:

Hierarchical clustering analysis using 2,621 prognostic genes previously identified by our group demonstrated that ccRCC patients with longer overall survival expressed lower levels of genes promoting proliferation or immune responses, while better maintaining gene expression associated with cortical differentiation and cell adhesion. Targets of 26 miRNAs were significantly enriched in the 2,621 prognostic genes and these miRNAs were prognostic by themselves. MiR-22 was associated with poor overall survival in the TCGA dataset. Overexpression of miR-22 promoted invasion of primary ccRCC cells in vitro and modulated transcriptional programs implicated in cancer progression including DNA repair, cell proliferation and invasion.

Conclusions:

Our results suggest that ccRCCs with differential clinical outcomes have distinct transcriptomes for which miRNAs could serve as master regulators. MiR-22, as a master regulator, promotes ccRCC progression at least in part by enhancing cell invasion.

Toward a genome-based treatment landscape for renal cell carcinoma

Knowledge about molecular mechanisms driving development and progression of renal cell carcinoma has been elucidated by different studies. In few years we discovered a large difference between genomic landscapes of clear cell and non-clear cell carcinoma. Moreover, tumor heterogeneity and different acquisition of gene mutations during tumor progression are issues of particular interest. In this review we focalized our attention on principal genomic alterations identified among RCC subtypes. Acquired gene mutations may be an adaptive response to several external pressure including metabolic, treatment, genomic and immune-related external pressure. Thus we correlated and discussed principal genomic alterations adopted by tumor to escape from each external pressures. The aim of the present work is to summarize current knowledge about genomic alterations in RCC with special interest of treatment strategies tailored on the basis of disease mutations assessment.

BAP1 in solid tumors

One of the most attractive cancer-related genes under investigation is BAP1. Reasons of this growing interest are related to the wide spectrum of pathways directly or indirectly modulated by this gene and shared by several solid tumors. Programmed cell-death, cell metabolisms, immune cells development, ferroptosis and defects in DNA damage response are only some of the multitude of processes depending on BAP1. Loss of this gene seems to occur in different times of tumor history. Moreover, times of BAP1 loss strongly diverge among primary tumors suggesting the presence of several and different triggering factors. Regardless of when it happens, BAP1 loss usually results in prognosis worsening and in the acquisition of more aggressive clinical features by cancer cells.

SETD2, GIGYF2, FGFR3, BCR, KMT2C, and TSC2 as candidate genes for differentiating multilocular cystic renal neoplasm of low malignant potential from clear cell renal cell carcinoma with cystic change

Purpose

Multilocular cystic renal neoplasm of low malignant potential (MCRNLMP) and clear cell renal cell carcinoma with cystic change (MCRCC) have different prognoses despite similar histologic characteristics. The aim of this study was to identify differentially mutated genes in resected tumor specimens from patients diagnosed with MCRNLMP and MCRCC using a kidney cancer gene panel.

Materials and Methods

Between 2009 and 2016, 13 MCRNLMP and 17 MCRCC cases were selected. Tumor tissues from 5 MCRNLMP and 16 MCRCC cases were subjected to gene sequencing to detect mutations among 88 genes selected from a kidney cancer gene panel after quality control. Fisher's exact test was used to compare gene mutation profiles between the two diseases. Genes were considered to be positive for mutation according to the presence of an in-frame/frameshift deletion or insertion, missense/nonsense mutation, or multi-hit mutation.

Results

During a median follow-up period of 66.2 months, there was only one case of MCRCC recurrence among all 30 patients. Target gene sequencing showed that 35 genes tended to be more frequently positive in either disease group, with six genes showing a significantly different frequency of mutation between the groups: GIGYF2 (odds ratio [OR], 5.735), FGFR3 (OR, 6.787), SETD2 (OR, 4.588), BCR (OR, 6.266), KMT2C (OR, 8.167), and TSC2 (OR, 4.474).

Conclusions

Six candidate genes showed significantly different mutation patterns between MCRNLMP and MCRCC, providing insight into their pathogenic mechanisms and differential prognoses.

The Association of Androgen Receptor Expression with Renal Cell Carcinoma Risk: a Systematic Review and Meta-Analysis

The relationship between androgen receptor expression and renal cell carcinoma risk remains controversial. This study is aimed to investigate the clinical significance of androgen receptor expression in renal cell carcinoma. A computerized bibliographic search of Embase, the PubMed, and Web of Science combined with manual research between 1977 and 2017 was conducted to explore the association between androgen receptor expression and clinicopathological features of renal cell carcinoma. Data were analyzed by a meta-analysis using RevMan 5.3 analysis software. Eleven retrospective studies with 1839 renal cell carcinoma cases were finally included according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. It was found that there was no significant difference between androgen receptor expression and susceptibility, pathological type, metastatic status, metastatic type (lymph or distant metastasis) and cancer-specific survival of renal cell carcinoma (P > 0.05). However, positive androgen receptor expression was demonstrated to be significantly associated with male patients, lower pathological grade, and earlier tumor stage of renal cell carcinoma (OR = 1.69, 95% CI = 1.30-2.19, P < 0.0001; OR = 2.06, 95% CI = 1.49-2.85, P < 0.0001; OR = 2.81, 95% CI = 1.30-6.12, P = 0.009; respectively). In conclusion, higher androgen receptor expression was correlated with male patients, low tumor grade and early stage of renal cell carcinoma. Based on current results, androgen receptor-inhibited target therapy for renal cell carcinoma patients may be of limited benefits and should be taken into more evaluations.

Growth and Proliferation of Renal Cell Carcinoma Cells Is Blocked by Low Curcumin Concentrations Combined with Visible Light Irradiation

The anti-cancer properties of curcumin in vitro have been documented. However, its clinical use is limited due to rapid metabolization. Since irradiation of curcumin has been found to increase its anti-cancer effect on several tumor types, this investigation was designed to determine whether irradiation with visible light may enhance the anti-tumor effects of low-dosed curcumin on renal cell carcinoma (RCC) cell growth and proliferation. A498, Caki1, and KTCTL-26 cells were incubated with curcumin (0.1–0.4 µg/mL) and irradiated with 1.65 J/cm² visible light for 5 min. Controls were exposed to curcumin or light alone or remained untreated. Curcumin plus light, but not curcumin or light exposure alone altered growth, proliferation, and apoptosis of all three RCC tumor cell lines. Cells were arrested in the G0/G1 phase of the cell cycle. Phosphorylated (p) CDK1 and pCDK2, along with their counter-receptors Cyclin B and A decreased, whereas p27 increased. Akt-mTOR-signaling was suppressed, the pro-apoptotic protein Bcl-2 became elevated, and the anti-apoptotic protein Bax diminished. H3 acetylation was elevated when cells were treated with curcumin plus light, pointing to an epigenetic mechanism. The present findings substantiate the potential of combining low curcumin concentrations and light as a new therapeutic concept to increase the efficacy of curcumin in RCC.

Fructose 1,6-Bisphosphatase 1 Expression Reduces 18F-FDG Uptake in Clear Cell Renal Cell Carcinoma

Purpose

To determine the relationship between fructose 1,6-bisphosphatase 1 (FBP1) expression and fluorine 18 (¹⁸F) fluorodeoxyglucose (FDG) uptake in patients with clear cell renal cell carcinoma (ccRCC), and to investigate how ¹⁸F-FDG uptake and FBP1 expression are related to tumor metabolism and tumor differentiation grade.

Materials and Methods

A total of 54 patients with ccRCC underwent ¹⁸F-FDG combined positron emission tomography and computed tomography (PET/CT) before tumor resection. The maximum standardized uptake value (SUVmax) for the primary tumor was calculated from the ¹⁸F-FDG uptake. The relationship between SUVmax of primary tumor and the expression of FBP1, hexokinase 2 (HK2), and glucose transporter 1 (GLUT1) was analyzed via immunohistochemical analysis.

Results

We identified an inverse relationship between FBP1 expression and SUVmax (P=0.031). SUVmax was higher in patients with high-grade ccRCC (mean, 11.6 ± 5.0) than in those with low-grade ccRCC (mean, 3.8 ± 1.6, P < 0.001). FBP1 expression was significantly lower in patients with high-grade ccRCC (mean, 0.23 ± 0.1) than in those with low-grade ccRCC (mean, 0.57 ± 0.08; P=0.018). FBP1 status could be predicted with an accuracy of 66.7% when a SUVmax cutoff value of 3.55 was used. GLUT1 expression in ccRCC was positively correlated with ¹⁸F-FDG uptake and FBP1 status, whereas HK2 expression was not.

Conclusion

SUVmax in patients with ccRCC is inversely associated with the expression of FBP1, and FBP1 may inhibit ¹⁸F-FDG uptake via regulating GLUT1. SUVmax is higher in patients with high-grade ccRCC than in those with low-grade ccRCC, which could be the result of lower FBP1 expression in patients with high-grade ccRCC.

Metastatic Renal Cell Carcinoma Presenting as a Bleeding Gastric Polyp

Background

Renal cell carcinoma (RCC) is responsible for nearly 13,000 deaths in the United States every year, predominantly because of metastasis to other bodily organs. However, metastasis of RCC to the stomach occurs rarely; it presents as solitary or multiple polyps or as ulcers concerning for primary gastric carcinoma. Bleeding from metastasis to the stomach is a rare and underrecognized cause of gastrointestinal bleeding. We describe a case of gastrointestinal bleeding in an elderly female who was found to have a gastric polyp of RCC origin.

Case Report

An 83-year-old female presented to our hospital for evaluation of an acute right basal ganglia hemorrhage after falling at her nursing home. Her hospital course was notable for melenic stool and anemia. Upper endoscopy revealed a single 40-mm pedunculated polyp and active bleeding on the lesser curvature of the stomach. Polypectomy and clipping were performed. Pathology was consistent with metastatic clear cell RCC. The patient's family declined a referral to oncology for evaluation of the newly diagnosed malignancy and opted for hospice care.

Conclusion

This case illustrates the potential for metastatic RCC to involve the stomach and cause gastrointestinal bleeding and anemia. The case also illustrates the role of upper gastrointestinal endoscopy in diagnosing and treating metastatic causes of gastrointestinal bleeding.

Phosphoinositide-dependent kinase 1-associated glycolysis is regulated by miR-409-3p in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most popular kidney cancer in adults. Metabolic shift toward aerobic glycolysis is a fundamental factor for ccRCC therapy. MicroRNAs (miRNAs) are thought to be important regulators in ccRCC development and progression. Phosphoinositide-dependent kinase 1 (PDK1) is required for metabolic activation; however, the role of PDK1-induced glycolytic metabolism regulated by miRNAs is unclear in ccRCC. So, the purpose of the current study is to elucidate the underlying mechanism in ccRCC cell metabolism mediated by PDK1. Our results revealed that miR-409-3p inhibited glycolysis by regulating PDK1 expression in ccRCC cells. We also found that miR-409-3p was regulated by hypoxia. Our results indicated that PDK1 facilitated ccRCC cell glycolysis, regulated by miR-409-3p in hypoxia.

Bioinformatic identification of key genes and analysis of prognostic values in clear cell renal cell carcinoma

The present study aimed to identify new key genes as potential biomarkers for the diagnosis, prognosis or targeted therapy of clear cell renal cell carcinoma (ccRCC). Three expression profiles (GSE36895, GSE46699 and GSE71963) were collected from Gene Expression Omnibus. GEO2R was used to identify differentially expressed genes (DEGs) in ccRCC tissues and normal samples. The Database for Annotation, Visualization and Integrated Discovery was utilized for functional and pathway enrichment analysis. STRING v10.5 and Molecular Complex Detection were used for protein-protein interaction (PPI) network construction and module analysis, respectively. Regulation network analyses were performed with the WebGestal tool. UALCAN web-portal was used for expression validation and survival analysis of hub genes in ccRCC patients from The Cancer Genome Atlas (TCGA). A total of 65 up- and 164 downregulated genes were identified as DEGs. DEGs were enriched with functional terms and pathways compactly related to ccRCC pathogenesis. Seventeen hub genes and one significant module were filtered out and selected from the PPI network. The differential expression of hub genes was verified in TCGA patients. Kaplan-Meier plot showed that high mRNA expression of enolase 2 (ENO2) was associated with short overall survival in ccRCC patients (P=0.023). High mRNA expression of cyclin D1 (CCND1) (P<0.001), fms related tyrosine kinase 1 (FLT1) (P=0.004), plasminogen (PLG) (P<0.001) and von Willebrand factor (VWF) (P=0.008) appeared to serve as favorable factors in survival. These findings indicate that the DEGs may be key genes in ccRCC pathogenesis and five genes, including ENO2, CCND1, PLT1, PLG and VWF, may serve as potential prognostic biomarkers in ccRCC.

Identification of potential crucial genes associated with carcinogenesis of clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is a common genitourinary malignancy with high mortality. However, the molecular pathogenesis of ccRCC remains unclear and effective biomarkers for daily practice are still limited. Thus, we aimed to identify the potential crucial genes and pathways associated with carcinogenesis of ccRCC and further analyze the molecular mechanisms implicated in tumorigenesis. In the present study, expression profiles GSE 66270, GSE 53757, GSE 36895, and GSE 76351 were downloaded from GEO database, including 244 matched primary and adjacent normal tissues, furthermore, the level 3 RNAseq dataset (RNAseqV2 RSEM) of KIRC was also downloaded from The Cancer Genome Atlas (TCGA), which consist of 529 ccRCC tumors and 72 normal tissues. Then, differentially expressed genes (DEGs) and pathway enrichment were analyzed by using R software. A total of 129 up- and 123 down-regulated genes were identified, which were aberrantly expressed both in GEO and TCGA data. Second, Gene ontology (GO) analyses revealed that most of the DEGs were significantly enriched in integral component of membrane, extracellular exosome, plasma membrane, cell adhesion, and receptor binding. Signaling pathway analyses indicated that DEGs had common pathways in signal transduction, metabolism, and immune system. Third, hub genes were identified with protein-protein interaction (PPI) network, including PTPRC, TGFB1, EGF, MYC, ITGB2, CTSS, FN1, CCL5, KNG1, and CD86. Additionally, sub-networks analyse was also performed by using MCODE plugin. In conclusion, the novel DEGs and pathways in ccRCC identified in this study may provide new insight into the underlying molecular mechanisms that facilitates RCC carcinogenesis.

Cell death-based approaches in treatment of the urinary tract-associated diseases: a fight for survival in the killing fields

Urinary tract-associated diseases comprise a complex set of disorders with a variety of etiologic agents and therapeutic approaches and a huge global burden of disease, estimated at around 1 million deaths per year. These diseases include cancer (mainly prostate, renal, and bladder), urinary tract infections, and urolithiasis. Cell death plays a key role in the pathogenesis and therapy of these conditions. During urinary tract infections, invading bacteria may either promote or prevent host cell death by interfering with cell death pathways. This has been studied in detail for uropathogenic E. coli (UPEC). Inhibition of host cell death may allow intracellular persistence of live bacteria, while promoting host cell death causes tissue damage and releases the microbes. Both crystals and urinary tract obstruction lead to tubular cell death and kidney injury. Among the pathomechanisms, apoptosis, necroptosis, and autophagy represent key processes. With respect to malignant disorders, traditional therapeutic efforts have focused on directly promoting cancer cell death. This may exploit tumor-specific characteristics, such as targeting Vascular Endothelial Growth Factor (VEGF) signaling and mammalian Target of Rapamycin (mTOR) activity in renal cancer and inducing survival factor deprivation by targeting androgen signaling in prostate cancer. An area of intense research is the use of immune checkpoint inhibitors, aiming at unleashing the full potential of immune cells to kill cancer cells. In the future, this may be combined with additional approaches exploiting intrinsic sensitivities to specific modes of cell death such as necroptosis and ferroptosis. Here, we review the contribution of diverse cell death mechanisms to the pathogenesis of urinary tract-associated diseases as well as the potential for novel therapeutic approaches based on an improved molecular understanding of these mechanisms.

Obstacles in Renal Regenerative Medicine: Metabolic and Epigenetic Parallels Between Cellular Reprogramming and Kidney Cancer Oncogenesis

CONTEXT

Regenerative medicine has recently presented a revolutionary solution to end-stage kidney disease. Reprogramming patients' own cells generates induced pluripotent stem cells that are subsequently differentiated to "kidney organoid," a structure that is anatomically and functionally similar to the kidney. This approach holds the promise of a transplantable, immunocompetent, and functional kidney that could be produced in vitro. However, caution must be taken due to the molecular-level similarities between induced pluripotent stem cells and renal cell carcinomas. As such, if cell reprogramming is not tightly controlled, it can lead to carcinogenic changes.

OBJECTIVE

Based on recent next-generation sequencing results and other supporting data, we identified three major molecular attributes of renal cell carcinoma: metabolic alterations, epigenetic changes, and miRNA-based alterations. Strikingly, these variations are mirrored in induced pluripotent stem cells, which are the main cell source of renal regenerative medicine. Our objective was to discuss the shared metabolic, epigenetic and miRNA-regulated characteristics and to abridge their significance in renal regenerative medicine.

EVIDENCE ACQUISITION

English-language literature was retrieved through PubMed.

EVIDENCE SYNTHESIS

Authors collected the published evidence and evaluated the content based on independent literature findings. Articles were filtered to include only highly relevant, recent publications that presented reproducible results by authorities of the field.

CONCLUSIONS

The kidney represents a unique metabolic environment that could be hijacked by induced pluripotent stem cells or by partially differentiated cells for oncogenic transformation. Future differentiation protocols must produce kidney organoids that are fully engaged in filtration function.

PATIENT SUMMARY

A new technology can produce mini-kidneys or kidney organoids. This review discusses some of the challenges this technology has to face, including its high oncogenic potential. Understanding these similarities will lead to the safe creation of new functional kidney units in patients with kidney failure.

Addressing the best treatment for non-clear cell renal cell carcinoma: A meta-analysis of randomised clinical trials comparing VEGFR-TKis versus mTORi-targeted therapies

AIM

Non-clear cell renal cell carcinoma (nccRCC) tumours include a heterogeneous group of malignancies that profoundly differ in terms of morphology, genetic profile, clinical behaviour and prognosis. The optimal treatment algorithm for nccRCC is still unknown and derived mainly from evidence available for ccRCC, being therefore represented by targeted agents against vascular endothelial growth factor and mammalian target of rapamycin (mTOR) pathways. We aimed to compare the efficacy of vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKis) and mTOR inhibitors (mTORi) for the treatment of nccRCC patients.

METHODS

Searching the MEDLINE/PubMed, Cochrane Library and American Society of Clinical Oncology Meeting abstracts prospective studies were identified. Data extraction was conduced according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The measured outcomes were progression-free survival (PFS), overall survival (OS) and the overall response rate (ORR).

RESULTS

Four randomised controlled trials were selected for final analysis, with a total of 332 patients evaluable for PFS. Treatment with TKi significantly reduced the risk of progression compared with mTORi (hazard ratio [HR] = 0.71; 95% confidence interval [CI] 0.60-0.84; p < 0.0001). This difference remained significant when sunitinib was compared with everolimus in first-line setting (HR = 0.67; 95% CI, 0.56-0.80; p < 0.00001). In the 332 patients evaluable for OS, no significant difference was found between TKi and mTORi (HR = 0.86; 95% CI, 0.67-1.12; p = 0.27). In the 176 evaluable patients, TKis therapy did not improve the ORR when compared with mTORi (relative risk [RR] = 2.21; 95% CI, 0.87-5.60; p = 0.09), even if treatment with sunitinib doubled the probability of achieving a tumour response.

CONCLUSIONS

Treatment with TKis significantly improves PFS, but not OS, when compared with mTORi. Moreover, sunitinib as first-line therapy reduces the risk of progression compared with everolimus; therefore, supporting the standard treatment paradigm broadly used for ccRCC patients. The relatively modest efficacy of available targeted therapies reinforces the need of future histology based, molecular driven therapeutic paradigm.

PDZK1 inhibits the development and progression of renal cell carcinoma by suppression of SHP-1 phosphorylation

Renal cell carcinoma (RCC) is one of the most aggressive urologic cancers, however, the mechanism on supporting RCC carcinogenesis is still not clear. By using gene expression profile analysis and functional clustering, PDZ domain-containing 1 (PDZK1) was revealed to be downregulated in human clear cell renal cell carcinoma (ccRCC) samples, which was also verified in several independent public ccRCC data sets. Using PDZK1 overexpression and knockdown models in ccRCC cell lines, we demonstrated that PDZK1 inhibited cell proliferation, cell cycle G1/S phase transition, cell migration and invasion, indicating a tumor-suppressor role in the development and progression of ccRCC. Our study further demonstrated that PDZK1 inhibited cell proliferation and migration of ccRCC via targeting SHP-1. PDZK1 was further identified to suppress cell proliferation by blocking SHP-1 phosphorylation at Tyr536 via inhibition of the association between SHP-1 and PLCβ3, and then retarding Akt phosphorylation and promoting STAT5 phosphorylation in ccRCC cells. Moreover, the inhibitive effects of PDZK1 on SHP-1 phosphorylation and the tumor growth were verified in vivo by xenograft tumor studies. Accordingly, PDZK1 expression was negatively correlated with SHP-1 activation and phosphorylation, advanced pathologic stage, tumor weight and size, and prognosis of ccRCC patients. These findings have provided first lines of evidences that PDZK1 expression is negatively correlated with SHP-1 activation and poor clinical outcomes in ccRCC. PDZK1 was identified as a novel tumor suppressor in ccRCC by negating SHP-1 activity.

Association of Vascular Endothelial Growth Factor Gene Polymorphism With Renal Cell Carcinoma Risk

The conclusion of the relationship between vascular endothelial growth factor gene polymorphism and renal cell carcinoma risk was inconsistent. This study was performed to assess the relationship between vascular endothelial growth factor gene polymorphism and renal cell carcinoma risk using meta-analysis. The association studies were identified from PubMed, Embase, and Web of Science, and eligible studies were included and calculated. Ten studies were included for this meta-analysis. vascular endothelial growth factor (VEGF) +405G > CC allele and GG genotype were associated with renal cell carcinoma risk for overall populations in this meta-analysis (C allele: odds ratio = 1.18, 95% confidence interval: 1.05-1.33, P = .004; CC genotype: odds ratio = 1.20, 95% confidence interval: 0.96-1.50, P = .12; GG genotype: odds ratio = 0.79, 95% confidence interval: 0.67-0.93, P = .004). Furthermore, VEGF +936C>T gene polymorphism and VEGF −2578 C>A gene polymorphism were associated with renal cell carcinoma risk for overall populations (+936C>T: T allele: odds ratio = 1.16, 95% confidence interval: 1.05-1.29, P = .004; TT genotype: odds ratio = 1.25, 95% confidence interval: 1.02-1.52, P = .03; CC genotype: odds ratio = 0.86, 95% confidence interval: 0.75-0.98, P = .03; −2578 C>A: A allele: odds ratio = 1.26, 95% confidence interval: 1.15-1.38, P < .00001; AA genotype: odds ratio = 1.39, 95% confidence interval: 1.16-1.67, P = .0004; CC genotype: odds ratio = 0.75, 95% confidence interval: 0.61-0.92, P = .006). However, VEGF −634G>C, VEGF −460T>C, VEGF −1154 G>A, and VEGF +1612 G>A gene polymorphisms were not associated with renal cell carcinoma risk. In conclusion, VEGF +405G>CC allele and GG genotype, VEGF +936C>T gene polymorphism, and VEGF −2578 C>A gene polymorphism were associated with renal cell carcinoma risk for overall populations. However, more studies should be performed to assess this relationship in the future.

VHL Inactivation in Precancerous Kidney Cells Induces an Inflammatory Response via ER Stress-Activated IRE1 Signaling

Mutations and epigenetic inactivation of the tumor suppressor gene von Hippel-Lindau (VHL) are major causes of clear-cell renal cell carcinoma (ccRCC) that may originate from chronic inflammation. However, the role of VHL loss of function in the development of ccRCC via inflammation remains poorly understood. VHL-mutant cells exhibit metabolic abnormalities that can cause chronic endoplasmic reticulum (ER) stress and unfolded protein response. We hypothesize that unresolved ER stress induces the inflammatory responses observed in ccRCC. ER stress markers including BiP and XBP1s were significantly increased in cultured and primary VHL loss-of-function kidney cells. In epithelial cells, the kinase activity of IRE1α was required for the induction of NF-κB and JNK and for the recruitment of macrophages. IRE1α kinase activity was also important for the development of fibrotic phenotype in conditional Vhlh knockout mice. Our results offer insights into the therapeutic potential against ccRCC development by relieving metabolic stress. Such cancer prevention strategy may be critical for high-risk cohorts such as the familial VHL disease patients. Cancer Res; 77(13); 3406-16. ©2017 AACR.

A Three-Variable Model Predicts Short Survival in Patients With Newly Diagnosed Metastatic Renal Cell Carcinoma

Background

Patients with metastatic renal cell carcinoma (mRCC) have variable survival outcomes. When discussing management approaches and providing information to patients and caregivers, it is important to have realistic perspectives, especially if the expected prognosis is very unfavorable. In the present study, factors predicting this endpoint were analyzed.

Methods

Data from 60 patients treated in routine clinical practice were evaluated. Unfavorable prognosis was defined as death within approximately 3 months from diagnosis of mRCC (maximum 3.5 months). Baseline factors including laboratory values and management approach were compared between the groups with short and longer survival.

Results

A total of 48 patients (80%) experienced ≥ 4 months survival (4+MS) and 10 (16.7%) experienced shorter survival (3MS). The others had short follow-up. Adverse prognostic factors that were significantly more frequent in the 3MS group were low hemoglobin, high lactate dehydrogenase and lack of systemic therapy. We used these three items to create a prognostic model: score 0 = no adverse factors, score 1 = one adverse factor, score 2 = two adverse factors, score 3 = three adverse factors. In the score 0 group, one out of 20 patients experienced 3MS (5%). In score 1, two out of 21 patients belonged to the 3MS group (9.5%). For score 2, the corresponding figure was four out of 14 patients (29%). In the score 3 group, three out of three patients experienced 3MS (100%) (P = 0.0001).

Conclusions

A simple model with three prognostic factors predicted survival of patients with newly diagnosed mRCC. Additional validation in other databases is warranted.

Metabolic Syndrome Negatively Impacts the Outcome of Localized Renal Cell Carcinoma

The aim of this study was to analyze the impact of metabolic syndrome (MetS) on outcome of patients with localized renal cell carcinoma (RCC). A retrospective database was compiled consisting of 646 patients who underwent surgery for localized RCC between 2005 and 2014. A total of 439 patients were eligible for final analysis. For diagnosis of MetS, the WHO criteria of 1998 were used. Median follow-up was 32 months (ranging from 2 to 119). Kaplan-Meier and log-rank analyses were performed to compare patients with and without MetS or its components. Univariate and multivariate logistic regression identified prognostic factors for progression-free survival (PFS), cancer-specific survival (CSS), and overall survival (OS). In our cohort, 9.8% (n = 43) of patients were diagnosed with MetS. There were no differences between patients with and without MetS regarding clinicopathological parameters with the exception of patients' age (p = 0.002). Kaplan-Meier and log-rank analyses revealed a shorter PFS for patients with MetS (p = 0.018), whereas no differences were found for each of the single components of MetS, namely, diabetes mellitus (DM) (p = 0.332), BMI >30 kg/m² (p = 0.753), hypertension (p = 0.451), and hypertriglyceridemia (p = 0.891). Logistic regression identified age (HR = 1.92, p = 0.03), tumor stage (HR = 4.37, p < 0.001), grading (HR = 4.57, p < 0.001), nodal status (HR = 3.73, p = 0.04), surgical margin (HR = 1.96, p = 0.04), concomitant sarcomatoid differentiation (HR = 5.06, p < 0.001), and MetS (HR = 1.98, p = 0.04) as independent factors for PFS. For CSS, only age (HR = 2.62, p = 0.035), tumor stage (HR = 3.06, p < 0.02), and grading (HR = 6.83, p < 0.001) were significant. In conclusion, patients with localized RCC and MetS show significantly reduced PFS and might profit from specific consultation and follow-up.